Ramipril Treatment Research Articles

Impact of Using Alternative Graft Function Endpoints: A Secondary Analysis of a Kidney Transplant Trial.

Nephrology trials assessing the impact of interventions on "standard" outcomes, such as doubling of creatinine, end-stage renal disease (ESRD), and/or death, are difficult to conduct given the time required for endpoints to accrue. The objective of this study was to determine if using lesser declines in kidney function would alter the interpretation of a previous randomized controlled trial. This study was a secondary analysis of a kidney transplant trial comparing the use of a 40% or greater, 30% or greater, or 20% or greater decline in estimated glomerular filtration rate (eGFR) as a substitute for doubling of serum creatinine. Declines in eGFR were determined relative to baseline. This trial enrolled 212 kidney transplant patients with proteinuria and assessed the clinical impact of ramipril versus placebo on a primary outcome of doubling of serum creatinine, ESRD, or death. In this analysis, the declines in eGFR replaced doubling of creatinine in the composite endpoint. Mean trial follow-up was 41 months. A time-to-event composite of death, ESRD, or a 40% or greater, 30% or greater, or 20% or greater eGFR decline occurred in 45 (26 placebo vs 19 ramipril), 68 (35 vs 33), and 99 (50 vs 49) patients, respectively. Substituting these eGFR declines for doubling of serum creatinine resulted in an increase of 12, 35, and 66 endpoints compared with the original trial. In all 3 eGFR declines, ramipril treatment was not associated with any statistically significant differences despite the increase in events. Substituting doubling of serum creatinine for lesser eGFR percentage decline thresholds did not alter trial interpretation but did increase the number of events.

Switching from ramipril to sacubitril/valsartan favorably alters electrocardiographic indices of ventricular repolarization in heart failure with reduced ejection fraction

Background: Angiotensin receptor neprilysin inhibitor (ARNI, sacubitril/valsartan) reduces sudden death in heart failure with reduced ejection fraction (HFrEF). Corrected QT (QTc), T-wave peak to T-wave end interval (Tp-e) and Tp-e/QTc are electrocardiographic indices of ventricular repolarization heterogeneity. We aimed to assess the effects of switching from ramipril to ARNI on electrocardiographic indices of ventricular repolarization.Methods: A total of 48 patients with HFrEF (mean age: 63.3 ± 11.7 years; 36 males, 77.1% ischaemic etiology) were enrolled. All patients had New York Heart Association functional class II–III, left ventricular ejection fraction ≤35% and previously switched from ramipril to ARNI treatment. The standard 12-lead electrocardiograms on ramipril treatment and 1 month after ARNI treatment were analysed; heart rate, QTc, Tp-e and Tp-e/QTc were calculated. Minnesota Living with Heart Failure Questionnaire (MLWHFQ) scores and N-terminal pro-BNP (NT-proBNP) values were recorded.Results: QTc (415.2 ± 19.7 ms vs. 408.5 ± 20.8 ms, p = 0.022), Tp-e (100.7 ± 13.8 ms vs. 92.9 ± 12.1 ms, p < 0.001), Tp-e/QTc (0.242 ± 0.028 vs. 0.227 ± 0.029, p = 0.003) and heart rate (73.2 ± 4.7 bpm vs. 71.1 ± 4.9 bpm, p = 0.027) were reduced after ARNI. ARNI switch associated with improvement in MLWHFQ scores (32.4 ± 7.1 ms vs. 22.6 ± 7.0 ms, p < 0.001) and reduction of NT-proBNP (2457 ± 1879 pg/ml to 1377 ± 874 pg/ml, p < 0.001). Pearson’s correlation analysis revealed moderate correlations of MLWHFQ score with Tp-e (r = 0.543, p = 0.001) and Tp-e/QTc (r = 0.556, p = 0.001).Conclusions: Switching from ramipril to ARNI favourably alters QTc, Tp-e and Tp-e/QTc in HFREF. ARNI reduces symptoms of HFREF assessed by MLWHFQ and lowers NT-proBNP levels. Reduction in Tp-e and Tp-e/QTc correlate with clinical improvement in patients with HFrEF.

Comparison of Efficacy between Ramipril and Carvedilol on Limiting the Expansion of Abdominal Aortic Aneurysm in Mouse Model

Abdominal aortic aneurysm (AAA) is a common condition that may be life-threatening when it is unrecognized. The aim of this study is to evaluate and compare the efficacy of ramipril and carvedilol on limiting AAA expansion in mouse model. A total of 36 experimental AAA mouse model was induced with the continuous infusion of angiotensin II (Ang II) in 20-week-old male apolipoprotein E-deficient mice. They were randomly divided into 3 treatment groups and fed orally for 8 weeks; saline alone, ramipril (2.5 mg/30g/d), or carvedilol (3.125 mg/30g/d), respectively. Aortic diameter (AD) was measured by micro-computed tomography, and the level of biomarkers of aortic tissue such as monocyte chemoattractant protein-1 (MCP-1) and tissue inhibitor matrix metalloproteinase-1 (TIMP-1) was evaluated. After treatment, AD of both ramipril and carvedilol group was smaller than in the saline group. The percentage change of AD in both ramipril and carvedilol groups was significantly smaller than that of the saline group. Pathologic examination revealed relatively well-preserved aortic walls in the ramipril group compared to the carvedilol and saline groups. The level of MCP-1 was markedly decreased in both the ramipril and carvedilol groups compared to the saline group. The level of TIMP-1 was higher in the carvedilol group when compared to either the saline or ramipril groups. Ramipril and carvedilol treatment shows similar efficacy in limiting AAA expansion in mouse model. Future clinical research would be warranted to validate these results.

Ramipril and left ventricular diastolic function in stable patients with pulmonary regurgitation after repair of tetralogy of Fallot

BackgroundMeasures of left ventricular (LV) systolic and diastolic function are known predictors of mortality after repair of tetralogy of Fallot. We aimed to characterise LV reverse remodelling achievable with ramipril therapy. Methods and resultsA blinded post-hoc analysis of baseline and 6-month follow-up echocardiograms from the APPROPRIATE (ISRCTN: 97515585) randomised double-blinded placebo-controlled trial of ramipril therapy was performed in 64 patients: 32 in ramipril and 32 in placebo group. Tissue Doppler systolic and diastolic myocardial velocities, mitral inflow velocities and time intervals were measured. Left atrial area and left atrial emptying fraction were calculated.There was significant increase in long axis shortening mean (standard deviation); MAPSE [1.9 (4.2) mm vs −0.2 (3.7) mm; p = 0.030], peak lateral systolic velocity; S′ lateral [1.0 (2.0) cm/s vs −0.3 (2.2) cm/s; p = 0.025], peak lateral early diastolic velocity; E′ lateral [0.57 (2.4) cm/s vs −3.3 (3.9) cm/s; p < 0.001], transmitral to lateral mitral annular early diastolic velocity ratio; E/E′ lateral [−0.7 (1.9) vs 1.5 (1.9); p < 0.001] over the study period in the ramipril compared to the placebo group. Significantly higher measurements were observed in the ramipril arm of the subgroup of patients with right ventricular restrictive physiology in terms of peak late diastolic velocity; A [5.9 (13.5) cm/s vs −5.8 (12.5) cm/s; p = 0.041] and early to late diastolic transmitral velocity ratio; E/A [−0.18 (0.42) vs 0.23 (0.48); p = 0.037]. ConclusionSix months' ramipril treatment appears to limit progression of both diastolic and systolic LV function in adults late after tetralogy of Fallot repair. With increased appreciation that even subtle LV disease predicts tetralogy of Fallot outcomes, further clinical trials of drug therapies are justified.

The effect of nebivolol and ramipril on selected biochemical parameters, arterial stiffness, and circadian profile of blood pressure in young men with primary hypertension: A 12-week prospective randomized, open-label study trial.

Background:The pleiotropic effects of hypotensive drugs should always be taken into consideration. There is limited data on the effect of such drugs on reducing global cardiovascular risk in young hypertensives. The aim of this study was to evaluate the effect of nebivolol and ramipril on biochemical parameters, arterial stiffness, and circadian profile of blood pressure (BP) in young men undergoing treatment for hypertension (HT).Methods:A total of 80 patients aged 16 to 28 years of age with grade 1 HT were enrolled into the prospective randomized, open-label trial. They were randomized to receive 5 mg of nebivolol or 5 mg of ramipril, daily. Arterial stiffness index (SI), the circadian profile of BP registered in ambulatory blood pressure monitoring (ABPM), and biochemical parameters—including lipid profile, insulinemia, glycemia, and high sensitivity C-reactive protein (hsCRP) levels—were evaluated before and after the twelve-week period.Results:After the treatment period, we observed significant decreases in both ABPM systolic blood pressure (SBP) in group of nebivolol (P = .0007) and ramipril (P = .0001) and in ABPM diastolic blood pressure (DBP) in group of nebivolol (P = .0018) and ramipril (P = .0006). Reductions in the nondippers percentage were found in group of nebivolol and ramipril (P = .0077, P = .0001 respectively). Ramipril treatment resulted in a significant plausible modification in high-density lipoprotein (HDL) (P = .0390), glucose (P = .0213), and hsCRP (P = .0053) concentrations, as well as decreased SI (P = .0009) value, while nebivolol treatment showed no such benefits.Conclusions:Despite the similar hypotensive effect of nebivolol and ramipril, ramipril seems to possess better clinical potential in reducing cardiovascular risk in young men with HT.

Mitigation of radiation myelopathy and reduction of microglial infiltration by Ramipril, ACE inhibitor.

Experimental study. To evaluate the efficacy of Angiotensin-converting enzyme inhibitor Ramipril, as a mitigator of radiation-induced spinal cord injury. Stony Brook University, Stony Brook, NY, USA. Total of 22 rats were irradiated with single doses of 23.6-33 Gy at the C4-T2 spinal levels. After irradiation, the rats were randomized to the radiation only control group and the Ramipril-treated (radiation + Ramipril) experimental group. Ramipril 1.5 mg/kg/day was given in the drinking water starting 1 week after radiation through the study duration. All the rats irradiated with 28.5-33 Gy became paralyzed at 125 ± 4 days, whereas no rats became paralyzed after 23.6 Gy. The time to develop paralysis was delayed to 135 ± 4 days in Ramipril-treated group (P < 0.001). H&E and LFB showed microscopic structural restoration and remyelination with Ramipril treatment. VEGF expression was increased in the irradiated spinal cord, and the number of VEGF-positive cells was significantly decreased by Ramipril treatment (P < 0.001). Immunohistochemical stain with Iba-1 showed increased microglial infiltration in the irradiated spinal cords. The number of Iba-1-positive microglia was significantly reduced by Ramipril treatment (P < 0.05). Ramipril reduced the rate of paralysis even at the paralysis-inducing radiation doses. It also significantly delayed the onset of paralysis. Neuroinflammation and endothelial cell damage may be the key mediators of radiation injury. Ramipril can be readily translatable to clinical application as a mitigatory of radiotherapeutic toxicity.

The win ratio approach did not alter study conclusions and may mitigate concerns regarding unequal composite end points in kidney transplant trials

ObjectivesThe aim of the study was to determine the impact of using the win ratio approach and investigate whether this approach alters the interpretations or conclusions of a randomized trial in kidney transplantation. Study Design and SettingWe present an application of the win ratio approach in a kidney transplant trial that assessed the clinical effectiveness of ramipril treatment vs. placebo. The primary composite outcome included the time to death, kidney transplant failure, or doubling of serum creatinine. We compare the win ratio to a conventional hazard ratio (HR) from the original trial. A win ratio with a lower 95% confidence limit greater than 1 indicates a positive treatment effect with statistical significance. ResultsFor the primary composite end point, ramipril treatment resulted in a win ratio of 1.21 (95% confidence interval [CI], 0.55-2.59) vs. a HR of 0.76 (95% CI, 0.38-1.51). With extended follow-up (mean 48 months), ramipril was associated with a win ratio of 1.02 (95% CI, 0.54-1.83) vs. a HR of 0.96 (95% CI, 0.55-1.65). ConclusionThe win ratio approach produced results similar to the original time-to-event analysis. Using this approach would not alter the conclusion of the original trial and lessens concerns associated with composite components of unequal clinical importance.

Clinical efficacy of African traditional medicines in hypertension: A randomized controlled trial with Combretum micranthum and Hibiscus sabdariffa.

Medicinal plants are widely used as a first-line therapy for hypertension, often without comparative clinical data. A prospective, randomized controlled trial was conducted to assess efficacy of Combretum micranthum (kinkeliba) and Hibiscus sabdariffa (bissap), in the galenic form of capsules of plant powder, on blood pressure in adult patients with non-complicated hypertension ( > 140/90 mm Hg). One hundred and twenty five patients were randomly allocated into group 1 (kinkeliba leaves 190 mg × 2/day), or group 2 (bissap calyx 320 mg × 2/day), or group 3 (ramipril 5 mg /day) during four consecutive weeks. Blood and urinary samples were collected on day 0 and 28 while patients' blood pressure was measured weekly. In all three groups SBP and DBP decreased over 3 weeks of treatment (P < 0.001). For SBP, mean decrease was higher with ramipril (-16.7 ± 8.4 mm Hg) than with kinkeliba (-12.2 ± 6.6 mm Hg, P = 0.016) and bissap (-11.2 ± 3.3 mm Hg, P = 0.001). For DBP, mean decrease with ramipril (-6.7 ± 3.6 mm Hg) was more important than with kinkeliba (-5.0 ± 3.0 mm Hg, P = 0.011) but not statistically different to bissap group (-6.0 ± 4.7 mm Hg, P = 0.271). A significant natriuretic effect was observed in the kinkeliba and bissap groups but not in patients under ramipril treatment. At the end of the four weeks, 39% [95% CI: 25.7-54.3] of patients in the ramipril group, 37% [95% CI: 23.6-51.9] of patients in the kinkeliba group and 21% [95% CI: 11.7-35.9] of those taking bissap had normalized their BP.

Abstract 115: Microvascular Response to Ramipril in Peripheral Artery Disease

Background: The myopathy of Peripheral Artery Disease (PAD), a consequence of ischemia caused by atherosclerotic plaques in arteries supplying the legs, is characterized by myofiber degeneration and fibrosis of the vascular walls and extramyofiber matrix. In association with fibrosis we have found a robust expression of the profibrotic cytokine TGFβ1 in vascular smooth muscle cells. Additionally, we have observed microvascular endothelial “swelling” in PAD muscle. Published data indicate that inhibitors of the angiotensin system reduce fibrosis in multiple organ systems and improve walking performance, in diverse patient populations. We hypothesize that “swelling” of microvasculature endothelial cells represents abnormal accumulation of basement membrane Collagen Type IV (Col-IV) and that treatment with Ramipril will improve the microvasculature. Methods and Results: Gastrocnemius biopsies of PAD patients at Fontaine Stage II (N=5) before and after six months of Ramipril intervention and control patients (N=4) were labeled with an antibody specific for Col-IV. Images were acquired with an automated wide-field microscope and then processed with Image Pro Plus® and AutoQuant® deconvolution software. We used Col IV label to measure wall thickness and lumen diameter of 230 to 360 microvessels per patient, with a custom MatLab program based on the Expectation Maximization algorithm coupled with a Gaussian Mixture Model. Microvessel wall thickness was significantly greater (p &lt; 0.04) in PAD patients before (1.54 ± 0.04 μ) and after (1.61 ± 0.06 μ) Ramipril treatment compared to control (1.42 ± 0.02). Lumen diameter was significantly greater (p &lt; 0.02) in Post-Ramipril (3.49 ± 0.04 μ) compared to Pre-Ramipril (3.18 ± 0.08 μ) and control (3.00 ± 0.11 μ) patients. Conclusions: The increase of microvessel lumen diameter with Ramipril treatment is expected to increase microvascular perfusion and thereby improve walking distance. Our study will be expanded to increase cohort size and evaluate the association of microvascular measurements with microperfusion determined by Contrast Enhanced Ultrasonography and with walking performance.

Modeling Disease Progression: Angiotensin II Indirectly Inhibits Nitric Oxide Production via ADMA Accumulation in Spontaneously Hypertensive Rats.

Nitric oxide (NO) production impairment is involved in the onset and development of hypertension. Although NO production impairment in spontaneously hypertensive rat (SHR) has been reported in a variety of researches, the time course of this progressive procedure, as well as its relationship with asymmetric dimethylarginine (ADMA) and angiotensin II (Ang II), has not been quantified. The aim of this research is to establish a mechanism-based disease progression model to assess Ang II and ADMA's inhibition of NO production in SHR's disease progression with/without ramipril's intervention. SHR were randomly divided into three groups: one disease group (n = 8) and two treatment groups (n = 8 for each group): standard treatment group (receiving ramipril 2 mg/kg*day) and intensive treatment group (receiving ramipril 10 mg/kg*day). ADMA, Ang II, NO, and SBP were determined weekly. Intensive treatment with ramipril was found to have no further attenuation of plasma NO and ADMA than standard treatment beyond its significantly stronger antihypertensive effects. Four linked turnover models were developed to characterize the profiles of ADMA, Ang II, NO, and SBP during hypertensive disease progression with/without ramipril intervention. Our model described Ang II and ADMA's contribution to NO production impairment and their responses to ramipril treatment throughout the disease progression in SHR. Model simulations suggested that Ang II affected NO production mainly through inhibiting ADMA elimination rather than affecting nitric oxide synthase (NOS) directly.

Effect of Ramipril Treatment on Proteinuria and Advanced Glycation End Products in Type 2 Diabetes Mellitus Patients with Nephropathy: One Year Follow up Study

Effect of Ramipril Treatment on Proteinuria and Advanced Glycation End Products in Type 2 Diabetes Mellitus Patients with Nephropathy: One Year Follow up Study

Angiotensin-converting enzyme inhibitor prevents oxidative stress, inflammation, and fibrosis in carbon tetrachloride-treated rat liver

Hepatic fibrosis is a common feature of chronic liver injury, and the involvement of angiotensin II in such process has been studied earlier. We hypothesized that anti-angiotensin II agents may be effective in preventing hepatic fibrosis. In this study, Long Evans female rats were used and divided into four groups such as Group-I, Control; Group-II, Control + ramipril; Group-III, CCl4; and Group-IV, CCl4 + ramipril. Group II and IV are treated with ramipril for 14 d. At the end of treatment, the livers were removed, and the level of hepatic marker enzymes (aspartate aminotransferase, Alanine aminotransferase, and alkaline phosphatase), nitric oxide, advanced protein oxidation product , catalase activity, and lipid peroxidation were determined. The degree of fibrosis was evaluated through histopathological staining with Sirius red and trichrome milligan staining. Carbon-tetrachloride (CCl4) administration in rats developed hepatic dysfunction and raised the hepatic marker enzymes activities significantly. CCl4 administration in rats also produced oxidative stress, inflammation, and fibrosis in liver. Furthermore, angiotensinogen-inhibitor ramipril normalized the hepatic enzymes activities and improved the antioxidant enzyme catalase activity. Moreover, ramipril treatment ameliorated lipid peroxidation and hepatic inflammation in CCl4-treated rats. Ramipril treatment also significantly reduced hepatic fibrosis in CCl4-administered rats. In conclusion, our investigation suggests that the antifibrotic effect of ramipril may be attributed to inhibition of angiotensin-II mediated oxidative stress and inflammation in liver CCl4-administered rats.

Angiotensinogen (AGT) M235T, AGT T174M and Angiotensin-1-Converting Enzyme (ACE) I/D Gene Polymorphisms in Essential Hypertension: Effects on Ramipril Efficacy.

Background:Hypertension, one of the most important risk factors for premature cardiovascular disease, is a major worldwide public health problem. Angiotensin-1-converting enzyme (ACE) and angiotensinogen (AGT) gene polymorphisms are thought to be associated with primary hypertension. In the present study, we examined the frequency of these gene polymorphisms in an adult population with and without essential hypertension. Furthermore, we evaluated the effect of ACE and AGT gene polymorphisms on ramipril treatment efficacy in the hypertensive patients.Methods:A total of 166 adults (83 hypertensives and 83 normotensives) were involved in the study and genotyped for AGTM235T (rs699), AGTT174M (rs4762) and ACEI/D (rs1799752) gene polymorphisms.Results:The genotype and allele distribution of the AGTM235T variant significantly differed between hypertensives and normotensives [odds ratio (OR) = 1.57% (T vs M allele), 95% confidence intervals (CIs): 1.01 - 2.44; p=0.045 for hypertensives]. However, none of the 3 studied Simple Nucleotide Polymorphisms were associated with the blood pressure-lowering response to ramipril.Conclusion:These results suggest that AGTM235T gene polymorphism is associated with essential hypertension. However, none of the AGTM235T, AGTT174M and ACEI/D gene polymorphisms influenced ramipril effectiveness.

Angiotensin converting enzyme inhibition increases ADMA concentration in patients on maintenance hemodialysis--a randomized cross-over study.

BackgroundEndothelial dysfunction occurs in patients with end-stage renal disease (ESRD) and is associated with increased cardiovascular morbidity and mortality. Asymmetric dimethylarginine (ADMA) contributes to endothelial dysfunction in ESRD. In the general population, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) decrease ADMA levels, but no study has compared the effect of these drugs in patients with ESRD on maintenance hemodialysis (MHD).MethodsWe evaluated the effect of 1-week treatment with ramipril (5 mg/d), valsartan (160 mg/d), and placebo on ADMA levels in 15 patients on MHD in a double-blind, placebo-controlled, three x three cross-over study.ResultsWe found that ADMA levels were increased at baseline and throughout the dialysis session during ramipril treatment (p < 0.001 compared to both, placebo and valsartan). Ramipril did not increase ADMA levels in a study of patients without ESRD, suggesting that factors related to ESRD or hemodialysis contribute to the ACE inhibitor-induced increase in ADMA. We have previously shown that ACE inhibition increases bradykinin (BK) levels during hemodialysis. We therefore evaluated the effect of bradykinin on ADMA production in A549 cells; a cell line that expresses BK receptors. Incubation with BK increased intracellular ADMA concentration through BK B2-receptor stimulation.ConclusionThese data indicate that short-term ACE inhibition increases ADMA in patients on MHD whereas ARBs do not. In vitro studies further suggest that this may occur through BK-mediated increase in ADMA production during ACE inhibition.Trial registrationClinicaltrials.gov NCT00732069 August 6 2008 and NCT00607672 February 4 2008Electronic supplementary materialThe online version of this article (doi:10.1186/s12882-015-0162-x) contains supplementary material, which is available to authorized users.

Randomised comparison of zofenopril and ramipril plus acetylsalicylic acid in postmyocardial infarction patients with left ventricular systolic dysfunction: a post hoc analysis of the SMILE-4 Study in patients according to levels of left ventricular ejection fraction at entry

ObjectiveConflicting evidence exists on the benefits of treating patients with coronary artery disease and preserved left ventricular ejection fraction (LVEF) with an ACE inhibitor. This retrospective analysis of the SMILE-4...

Bedtime hypertension chronotherapy: concepts and patient outcomes.

Recent findings indicate cardiovascular disease (CVD) risk is best predicted by asleep systolic blood pressure (SBP), and lowering it by scheduling ≥1 conventional long-acting hypertension medications, alone or in combination, at bedtime significantly lessens vascular-associated risks. Some 20 years ago, four controlled-onset extended-release drug-delivery systems incorporating a calcium channel or β-blocker, with the treatment goal specifically being attenuation of morning rather than asleep BP, were conceived as one type of bedtime hypertension chronotherapy. However, the CONVINCE outcomes trial failed to substantiate the merit of targeting morning and daytime BP to decrease CVD risk. The HOPE trial, entailing bedtime ramipril treatment for high CVD risk patients, showed substantial reduction of vascular-related events, theorized as the beneficial treatment-time-dependent strong asleep BP lowering. The MAPEC trial was the first prospective randomized treatment-time outcomes investigation to test the worthiness of bedtime hypertension chronotherapy entailing ≥1 conventional long-acting medications (BTCT), in comparison to the conventional morning-time therapeutic scheme for all medications (CMTT), to normalize asleep BP and diminish CVD risk. BTCT compared to CMTT significantly better lowered asleep BP and most importantly major CVD-associated morbidity and mortality, including myocardial infarction and ischemic and hemorrhagic stroke, by ~60%. CVD risk reduction was strongest when the BTCT included an angiotensin receptor blocker. The HOPE and MAPEC trials provide positive evidence of very significant CVD risk reduction by a BTCT strategy that specifically targets normalization of asleep BP, evidence that awaits conformation by the ongoing Hygia and other outcomes trials.

Abstract 17481: MicroRNAs Mediate the Protective Effect of Angiotensin Converting Enzyme Inhibition (ACEi) on the Heart in Rat Model of Acute Kidney Injury

Introduction: Cardiovascular complications are common in patients with kidney disease. MicroRNAs play an important role in regulating cell death pathways and cardiac hypertrophy but it is not known whether cardiac microRNAs contribute to cardio-renal cross talk. microRNA-1 and microRNA-133 are associated with cardiac fibrosis and apoptosis after myocardial infarction, whilst microRNA-212/132 is associated with cardiac hypertrophy. Aim: Using a rat model we investigated whether acute kidney injury leads to changes in cardiac microRNAs (1,133,212 and 132) and their gene targets. We also tested the effect of treatment with the angiotensin converting enzyme inhibitor (ACEi) ramipril on these cardiac microRNAs. Methods: Heart tissues were collected from rats 10 days after subtotal nephrectomy (STNx) surgery, where one kidney was removed and the other partially ligated (n=9), from sham animals (n=9), and from STNx rats treated with ramipril (n=9). RNA was extracted from the left ventricle and quantitative real time PCR was used to measure microRNA and their target gene expression levels. Results: In rats with renal injury, there was a significant increase in left ventricular hypertrophy (P&lt;0.05 vs sham). There was also a significant increase in expression of cardiac microRNA-212 (2 fold, P&lt;0.05 vs Sham) and microRNA-132 (3 fold, P&lt;0.05 vs Sham). Ramipril treatment in STNx rats attenuated the increase in microRNA-212 and caused a significant increase in expression of microRNA-133 (P&lt;0.001 vs Sham, P&lt;0.001 vs STNx+Veh) and microRNA-1 (P&lt;0.01 vs Sham, P&lt;0.01 vs STNx+Veh). Renal injury induced left ventricular hypertrophy was attenuated in ramipril treated STNx rats (P&lt;0.001 vs STNx+Veh). We also found altered expression of caspase 9, fibronectin 1, collagen 1A1 and forkhead box O3, all known for their involvement in the regulation of apoptosis, fibrosis and hypertrophy in cardiac cells, whilst being targets for the above microRNAs. Conclusions: The involvement of microRNAs in cardiac pathologies associated with kidney injury is a novel finding of our study. Our finding suggests an involvement of microRNA-1, microRNA-133 and microRNA-212/132 in the cardioprotective action of ACE inhibition in acute kidney injury.

Abstract 230: Angiotensin-Converting Enzyme Inhibition Increases ADMA Concentration in Patients on Hemodialysis

Endothelial dysfunction occurs commonly in patients with end-stage renal disease (ESRD) and is associated with increased cardiovascular morbidity and mortality. Asymmetric dimethylarginine (ADMA), an inhibitor of nitric oxidase synthase, is elevated in patients with chronic kidney disease and contributes to endothelial dysfunction in ESRD. In the general population, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) decrease ADMA levels, but no study has compared the effect of these drugs in patients with ESRD on hemodialysis. We therefore evaluated the effect of one-week treatment with ramipril (5 mg/d), valsartan (160 mg/d) and placebo on ADMA levels in fifteen patients on hemodialysis in a previously published double-blind, placebo-controlled, 3X3 cross-over study. We found that ADMA levels were increased at baseline and throughout the dialysis session during ramipril treatment (Figure 1, p&lt;0.001 compared to both placebo and valsartan). Ramipril did not increase ADMA levels in a study of patients without ESRD, suggesting that factors related to ESRD or hemodialysis contribute to the ACE inhibitor-induced increase in ADMA levels. We have previously shown that ACE inhibition increases bradykinin (BK) levels during hemodialysis. Therefore, we evaluated the effect of BK on ADMA production in A549 cells; incubation with BK increased intracellular ADMA concentration through bradykinin B2- receptor (B2R) stimulation (Figure 2). In conclusion, ACE inhibition increases ADMA in patients on hemodialysis. Studies in vitro suggest that this could occur through a bradykinin-mediated increase in ADMA production.

Ramipril protects the endothelium from high glucose-induced dysfunction through CaMKKβ/AMPK and heme oxygenase-1 activation.

This study aims to investigate the effects of ramipril (RPL) on endothelial dysfunction associated with diabetes mellitus using cultured human aortic endothelial cells (HAECs) and a type 2 diabetic animal model. The effect of RPL on vasodilatory function in fat-fed, streptozotocin-treated rats was assessed. RPL treatment of 8 weeks alleviated insulin resistance and inhibited the decrease in endothelium-dependent vasodilation in diabetic rats. RPL treatment also reduced serum advanced glycation end products (AGE) concentration and rat aorta reactive oxygen species formation and increased aorta endothelium heme oxygenase-1 (HO-1) expression. Exposure of HAECs to high concentrations of glucose induced prolonged oxidative stress, apoptosis, and accumulation of AGEs. These effects were abolished by incubation of ramiprilat (RPT), the active metabolite of RPL. However, treatment of HAECs with STO-609, a CaMKKβ (Ca(2+)/calmodulin-dependent protein kinase kinase-β) inhibitor; compound C, an AMPK (AMP-activated protein kinase) inhibitor; and Zn(II)PPIX, a selective HO-1 inhibitor, blocked these beneficial effects of RPT. In addition, RPT increased nuclear factor erythroid 2-related factor-2 (Nrf-2) nuclear translocation and activation in a CaMKKβ/AMPK pathway-dependent manner, leading to increased expression of the Nrf-2-regulated antioxidant enzyme, HO-1. The inhibition of CaMKKβ or AMPK by pharmaceutical approach ablated RPT-induced HO-1 expression. Taken together, RPL ameliorates insulin resistance and endothelial dysfunction in diabetes via reducing oxidative stress. These effects are mediated by RPL activation of CaMKK-β, which in turn activates the AMPK-Nrf-2-HO-1 pathway for enhanced endothelial function.

Secretion of adiponectin from human subcutaneous and omental adipose tissue: effects of ramipril and TNFα

Adiponectin secreted by adipose tissue, an insulin sensitizer, has beneficial effect in type 2 diabetes mellitus (T2DM). The study was designed to test the effect of anti-diabetic agent pioglitazone, antihypertensive agent ramipril and Tumor necrosis Factor α (TNF α) on adiponectin secretion from human adipose tissue in depot dependent manner. Subcutaneous adipose tissue (SAT) and omental adipose tissues (OAT) were obtained from 19 subjects (six non-obese controls, seven obese and six diabetic patients). Adipose tissue was treated with pioglitazone, ramipril and TNF α. Adiponectin secreted into the culture medium after treatment at different time interval (0, 24, 48, 96 h) was determined by ELISA and normalized for cellular DNA content. Pioglitazone and ramipril stimulated while TNFα inhibited (~10–40 %) adiponectin secretion. Responsiveness to ramipril and pioglitazone treatment was more in SAT. Interestingly diabetic patients show 40 % higher stimulation of adiponectin secretion in response to ramipril treatment than pioglitazone. These data suggest that, SAT, appears to be a major contributor to regulation of adiponectin in circulation. The effects of pioglitazone and ramipril, in improving adipose tissue function may contribute to reducing the risk of vascular diseases and the development of T2DM.